• Korean Journal of Pharmacognosy
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• v.27 no.4
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• pp.289-294
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• 1996

In previous paper, we described the induced callus of Corydalis remota contains a significant amount of alkaloids. This study describes an optimal condition to maximize alkaloid production. The suspension cultures maintained alkaloid production ability after fifth subculture and a small amount of alkaloid seemed to be released out of cells. The yields of alkaloid by cultured cells was varied depending on the concentrations of NAA, carbon sources and phosphate ion and depending on the vitamin combinations and concentrations. Biosynthetic precursor and an elicitor treatment also affected the total alkaloid yield of the cultures. The optimal conditions for alkaloid production were as follows: 1) MS basal salt containing 30 g/l of glucose, 1.0 mg/l of NAA, and vitamins of LS medium should be used. 2) The culture should be treated with tyrosine 20 mg/l, and yeast extract 1.5 ml/l after the culture reached a stationary phase of growth. Five alkaloids were isolated from the cultures and they were characterized. The spectral data unambiguously revealed that the isolated compounds were dihydrosanguinarine, protopine. tetrahydropalmatine, allocyptopine and ambinine, respectively.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.10a
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• pp.140-153
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• 2005

During the tunnel construction the major failure mode can be categorized as: tunnel failure just after the tunnel excavation without support, failure after application of shotcrete and finally failure after setting the concrete lining. The failure mode just after the tunnel excavation without support, can be further classified as : bench failure, crown failure, face failure, full face failure, failure due to weak strata and failure due to overburden. Moreover the failure after application of shotcrete is classified as heading face failure, settlement of shotcrete support, local failure of shotcrete lining and invert shotcrete. To find out the major causes of tunnel collapse, the investigation was done in case of the second phase of Seoul subway construction. The investigation results depicted that the major causes of tunnel collapse were due to the weak layer of rock/fault and sudden influx of ground water from the tunnel crown. While the investigation results of the mountain road tunnels construction have shown that the major causes of tunnel failure were inadequate analysis of tunnel face mapping results, intersection of faults and limestone cavities. In this paper some recent measurement in order to mitigate such tunnel collapse are presented

• Proceedings of the Korean Geotechical Society Conference
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• 2005.10a
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• pp.469-478
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• 2005

Understanding of an accurate state of consolidation of underconsolidated clay body, like a recently dredged or reclaimed clay deposits, is one of the most difficult tasks. The estimation of the consolidation status of these clay bodies is often made by laboratory tests of numerical analyses. However these methods demonstrated crucial limitations in the accurate prediction. Therefore, the predicted degree of consolidation from various techniques is verified by actual measured field data. The degree of consolidation of clay body in the East Side Hinterland of Gwangyang Port(2nd Phase) is evaluated in this study by using various techniques such as oedometer test, CPTu, numerical analysis and piezometer tests etc. And the results are compared each other to find the most reliable prediction technique. The merit and reliability of each method is discussed in detail. It is revealed from in this study that the estimation of degree of consolidation by an actual pore water pressure measurements is the most reliable technique.

• Korea-Australia Rheology Journal
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• v.16 no.3
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• pp.135-140
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• 2004

Morphological and rheological properties of the poly(methyl methacrylate) (PMMA) and polystyrene (PS) blends were studied by scanning electron microscopy (SEM) and advanced rheometric expansion system (ARES). From the SEM results, the PMMA-PS blends showed dispersed morphology and the particle size of the dispersed phase was quite small (0.1~0.6 $\mu\textrm{m}$ compared with other immiscible polymer blends. Values of the interfacial tension of the PMMA-PS blend were obtained from the Choi-Schowalter and the Palierne emulsion models using the storage modulus of the PMMA and PS, and found to be 1.0 and 2.0 mN/m, respectively. The interfacial tension between the PMMA and PS was also calculated from the Flory-Huggins polymer-polymer interaction parameter ($\chi$) and found to be from 0.98 to 1.86 mN/m depending on the molecular weight and composition. Comparing the values of the interfacial tension from the Flory-Huggins polymer-polymer interaction parameter and the values measured by oscillatory rheometer, it is suggested that the interfacial tension of the PMMA-PS blend obtained from the polymer-polymer interaction parameter are in good agreement with the values obtained by rheological measurements.

• Microbiology and Biotechnology Letters
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• v.17 no.1
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• pp.63-68
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• 1989

The optimum conditions for cellular autolysis in Clostridium butyricum ID-113 have been investigated. Cellular autolysis was optimal at pH 1.0 in 0.05 M potassium phosphate buffer and at 37$^{\circ}C$. The rate of cellular autolysis depended on the age of culture. The most rapid cellular autolysis occurred in the cells of mid-exponentially growing cultures, but cellular autolysis decreased sharply when the cultures entered the stationary phase. A growing culture of Cl. butyricum ID-113 was induced to autolyze and lost its turbidity spontaneously in the hypertonic NaCl, sucrose, or glucose medium. The autolytic enzyme activity was found In the autolysate of cells and the supernatant of the culture.

• Journal of Microbiology and Biotechnology
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• v.20 no.1
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• pp.138-145
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• 2010

A bacterial strain isolated from soil for its potential to control the anthracnose disease caused by Colletotrichum gloeosporioides was identified as a Bacillus subtilis. Bacillus subtilis CMB32 produced antifungal agents on M9 broth at $30^{\circ}C$. Biosurfactant lipopeptides produced by Bacillus subtilis CMB32 were precipitated by adjusting to pH 2 and extracting using chloroform/methanol, and then were purified using column chromatography and reverse-phase HPLC. The molecular masses of the lipopeptides were estimated by MALDI-TOF mass spectrometry as (a) 1,080, (b) 1,486, and (c) 1,044 Da, respectively. They had cyclic structures and amino acid compositions of (a) Pro, Asx, Ser, Tyr, Glx, (b) Glx, Tyr, Thr, Ala, Pro, lie, and (c) Glx, Leu, Val, Asx, respectively. Further analysis revealed that Bacillus subtilis CMB32 produced three antifungal lipopeptides: (a) iturin A, (b) fengycin, and (c) surfactin A.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.929-932
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• 2011

We developed a valve actuator controller for thruster system. This thruster system has four actuators and the actuator use a BLDC motor. Controller was made based on system and control requirement. The controller is consist of power, control and Amp. The control module use a micro-controller which is TMS320F28335 of Texas Instruments. It works for digital PID control and CAN communication and system control. The amp module for three phase BLDC motor use IGBT.

• Journal of Chest Surgery
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• v.41 no.6
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• pp.799-802
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• 2008

Infection occurs very rarely in the sternoclavicular joint compared to other joints in the body. It occurs mainly in IV drug abusers, diabetics, chronic renal failure patients, septic patients and those with central vein catheters. In the early phase, it can be treated simply by antibiotics or incision, and drainage. However, when proper treatment is not begun. early, bone destruction can occur, and only en-bloc resection of the involved bone can cure it. To reduce the risk of recurrence, we advanced a pectoralis major flap into the resected area based on the feeding artery. We report a case of a patient with sternoclavicular osteomyelitis who was successfully treated using en-bloc resection and a pectoral advancement flap.

• Corrosion Science and Technology
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• v.14 no.6
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• pp.301-312
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• 2015

Corrosion of zirconium fuel cladding is known to limit the lifetime and reloading cycles of fuel in nuclear reactors. Oxide layers formed on ZIRLO4^{TM}$ cladding samples, after immersion for 300-hour and 50-day in a simulated primary water chemistry condition ($360^{\circ}C$ and 20 MPa), were analyzed by using the scanning transmission electron microscopy (STEM), in-situ transmission electron microscopy (in-situ TEM) with the focused ion beam (FIB) technique, and X-ray diffraction (XRD). Both samples (immersion for 300 hours and 50 days) revealed the presence of the ZrO sub-oxide phase at the metal/oxide interface and columnar grains developed perpendicularly to the metal/oxide interface. Voids and micro-cracks were also detected near the water/oxide interface, while relatively large lateral cracks were found just above the less advanced metal/oxide interface. Equiaxed grains were mainly observed near the water/oxide interface.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.553-556
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• 2008

We hereby report novel driving scheme to eliminate effect of "residual" image sticking (RRI) problem which arises due to hysteresis problem in Thin Film Transistor (TFT) in AMOLED Displays. The driving scheme applies "black" voltage after every data voltage period in order to drive AMOLED in uni-direction. The system can be easily implemented with 120 Hz driving scheme which is well matured in AMLCD industries. Our analyses show systematic evaluation of the problem and thereby solving it by simple methods which will be significantly effective of driving OLED towards mass manufacturing stage.